Q: There is an increased risk of atypical femoral fractures after five years of treatment with bisphosphonates. What is the treatment strategy for patients who have responded to treatment and have completed five years on bisphosphonates?

There is insufficient information relating to this patient group to give firm guidelines. Most take the approach that if the patient has responded sufficiently, such that they have a bone mineral density that is no longer in the osteoporotic range, treatment can be stopped.

A repeat bone density scan might be performed a few years later to ensure the response is sustained.

In people who respond less well to five years of bisphosphonate treatment, switching to an alternative medication (for example, strontium ranelate) with a different mechanism might be appropriate. Decisions need to be on a case by case basis.

Q: What is the treatment pathway for patients who have shown a partial response to bisphosphonates after five years and who have not had any fractures?

It is difficult to know whether patients have actually responded to treatment, as the change in bone density does not correlate well with the reduction in fracture risk during bisphosphonate treatment. In patients who appear to remain at high risk of fracture after five years of treatment, continuing the bisphosphonate is entirely reasonable.

This is done on the basis that there is a small but important risk of the patient developing an atypical fracture, but the benefits are likely to outweigh the risks.

Q: Premenopausal women on long-term steroids are routinely given bisphosphonates and calcium on a prophylactic basis. Why would specialist advice be needed in this situation?

Glucocorticoid-induced osteoporosis should be regarded as distinct from postmenopausal osteoporosis. Bisphosphonates have been reported to reduce the effects of glucocorticoids on osteoblasts and this could account for the use of the medication in this context (something that is not relevant to postmenopausal osteoporosis).

There is actually little evidence to support the effectiveness of this treatment in premenopausal women. The data is extrapolated from RCTs that included a limited number of premenopausal women and subanalysis, but there were insufficient subjects to assess effectiveness in this subgroup.

Perhaps most significantly, bisphosphonates work in postmenopausal osteoporosis by reducing the elevated levels of bone resorption. HRT is an effective treatment in this context but premenopausal women effectively have their own supply of hormones.

Clinical trials of combined HRT and bisphosphonates have been disappointing. As such, the chance of a benefit with bisphosphonates in estrogen-replete premenopausal women appears minimal and unlikely to outweigh the risks associated with therapy.

Q: Is there a potential role for vitamin K intake in osteoporosis prevention?

Vitamin K intake in osteoporosis is interesting but controversial. There is no RCT demonstrating a clinically important benefit of vitamin K supplementation in terms of fracture risk. The same applies to other nutrients which may or may not have a role in bone health.

A healthy diet should be encouraged but high doses of individual dietary components cannot be recommended on the basis of bone health.

Q: What should be done if dental treatment is needed while the patient is on bisphosphonates?

Standard dental care, including extractions, can be carried out. However, complicated dental surgery should be avoided.

Dr Ghurye is a GP on the Isle of Wight and Dr Cooper is senior lecturer in endocrinology at the University of Birmingham and Queen Elizabeth Hospital, Birmingham.